We were all pretty excited about getting these 5 gallon IMS tanks. Then disappointed when the wings started flaring out. The tank banging around has been bugging me because the banging works the petcocks loose and they start leaking.

I finally got the ambition to disconnect all four petcocks and pull the tank off (guess it wasn’t bugging me that much). My tank has flared about three inches, an inch and a half on each side. Squeezing the wings together, with the tank off the bike, causes the inside hump of the tank “the saddle” to move up. The frame under the tank “the backbone” has marks on it where the tank was hitting.

Tank flare theory:
Highway wind flares the tank wings out and the tank flares until the tank saddle hits the frame backbone. The backbone stops it. If the gap between the tank and frame were filled in then the tank won’t flair.

I had an old inner tube, a heavy duty 1/8” one, cut some strips out and zip-tied them to the frame. It took about 3/8” to fill in the gap. With the gap filled the seat is a PIA to put on, and once you get the seat on the front of the tank pops up making it hard to get the front bolt in. After a few rides the tank re-forms and you can get it on without problems.

Nice work. I am still considering Ibarras solution for the support concerns:http://www.advrider.com/forums/showp...&postcount=132
I will try the tube fill trick and see what it does...did it make the tank move more forward? I can't have the tank move forward as I have a Scotts Damper Tower mounted and don't have any clearance...

Ya, I saw your post on the steering damper. My tank mount pin used to be all the way forward like yours. With the spacer in there the mount pin has moved back to about 1 1/8”. Good news is that it is tunable, adjusting the spacers you can move the tank pin from all the way forward to at least the mid slot position.

Ya, I saw your post on the steering damper. My tank mount pin used to be all the way forward like yours. With the spacer in there the mount pin has moved back to about 1 1/8”. Good news is that it is tunable, adjusting the spacers you can move the tank pin from all the way forward to at least the mid slot position.

what? the tank mount pin is movable?

how come all the people who had trouble getting their IMS tanks to fit over the pins didn't do this?

Ya, I saw your post on the steering damper. My tank mount pin used to be all the way forward like yours. With the spacer in there the mount pin has moved back to about 1 1/8”. Good news is that it is tunable, adjusting the spacers you can move the tank pin from all the way forward to at least the mid slot position.

I need the pin to remain forward in the slot so the tank needs to stay rearward of the head tube for clearance between the bolt on tower and the tank. As you can see as the tank sits now the tower pin actually touches the pin...

how come all the people who had trouble getting their IMS tanks to fit over the pins didn't do this?

The pin is not moving, the tank is being manipulated by the spacer and that is pulling the slot of the tank rearward. It would have kept me from using the dremel on my tank if I had tried Xfools spacer mod first...

Success!. I have put about 2000 more miles on the bike and the flare has stabilized at ½”. See post #4 for a pic of ½” flare.

You have to force everything together when you first put the spacers in. Put the seat on first, the front of the tank will pop up and you can then sit on it and get the bolt in on the front of the tank. After a couple of rides the tank will re-form and you will be able to get the seat on and off without problems.

One other note: the front of the seat is held down by two aluminum tangs welded to the frame. I’m sure those tangs are fragile and won’t hold up to being bent. So…… while “forcing” things together you need to adjust the backbone spacers in stages to avoid overstressing the tangs. I didn’t have a problem, just a warning for the over zealous when the use of “force” is suggested. Be gentle, do it in stages, put a couple of rides in to let the tank reform.

While I’m on the podium, Fuel Slosh in these 5 gallon IMS tank is awful, it completely screwed the handling of my bike. Stuffing your tank with G-Zero foam eliminates slosh, the stuff rocks and I am going to keep ranting about slosh in these large tanks until someone agrees with me.

Tank flare theory:
Highway wind flares the tank wings out and the tank flares until the tank saddle hits the frame backbone. The backbone stops it. If the gap between the tank and frame were filled in then the tank won’t flair...

Is this working for others? My 4.3 gallon is not responding. I'm thinking about attaching (maybe with epoxy?) some sort of lug to the bottom of each side to try to pull the tank back into shape.